--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/tests/gov/nasa/jpf/util/OATHashTest.java	Fri Jan 23 10:14:01 2015 -0800
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is licensed under the
+ * Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0. 
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+
+package gov.nasa.jpf.util;
+
+import java.util.HashSet;
+import java.util.Random;
+
+import org.junit.Test;
+
+import gov.nasa.jpf.util.test.TestJPF;
+import static gov.nasa.jpf.util.OATHash.*;
+
+/**
+ * just the very basic sanity checks for a hash function.
+ * <2do> should add a test for uniformity of hash vals and measure collisions in medium bin size constraints
+ */
+public class OATHashTest extends TestJPF {
+
+  @Test
+  public void testRandom(){
+    int maxRounds = 256;
+    int maxKey = 8;
+    Random r = new Random(42);
+    HashSet<Integer> seen = new HashSet<Integer>(); // not very smart, but the number of rounds is reasonably small
+    
+    for (int i=0; i<maxRounds; i++){
+      int h = 0;
+      for (int j=0; j<maxKey; j++){
+        int x = r.nextInt();
+        h = hashMixin(h, x);
+        
+        if (j>0){
+          System.out.print(',');
+        }
+        System.out.print(Integer.toHexString(x));
+      }
+      h = hashFinalize(h);
+      System.out.print(" => ");
+      System.out.println(h);
+      
+      if (seen.contains(h)){
+        fail("collision on round " + i);
+      }
+      seen.add(h);
+    }
+  }
+  
+  @Test
+  public void testRandomSmall(){
+    int maxRounds = 256;
+    int maxKey = 4;
+    int maxVal = 32;
+    Random r = new Random(42);
+    HashSet<Integer> seen = new HashSet<Integer>(); // not very smart, but the number of rounds is reasonably small
+    
+    for (int i=0; i<maxRounds; i++){
+      int h = 0;
+      for (int j=0; j<maxKey; j++){
+        int x = r.nextInt(maxVal);
+        h = hashMixin(h, x);
+        
+        if (j>0){
+          System.out.print(',');
+        }
+        System.out.print(x);
+      }
+      h = hashFinalize(h);
+      System.out.print(" => ");
+      System.out.println(h);
+      
+      if (seen.contains(h)){
+        fail("collision on round " + i);
+      }
+      seen.add(h);
+    }
+  }
+  
+}